Text (US+errata): Until end of turn, you may play cards from your graveyard. ; If a card would be put into your graveyard this turn, exile that card instead. [Oracle 2009/07/08]
If you play a Buyback spell (see Rule 702.24), then there will be two effects trying to replace where the card goes. You get to choose if the Buyback returns the card to your hand or the card gets removed from the game. [bethmo 1998/10/12]
To "play a card" is to either announce a spell or to put a land into play using the main phase special action. [D'Angelo 1999/01/18]
If an effect asks you to discard a card, you cannot "discard" something that is in your graveyard. Those cards are not in your hand for any reason other than letting you play them. Thus, Cycling abilities of cards in the graveyard cannot be used. [DeLaney 1998/10/15]
If you play a card using Yawgmoth's Will and something triggers only when "played from your hand", that something will not trigger. [bethmo 1999/03/05] Such things trigger based on where the card came from.
It does not look back in time. It only removes cards from the game that go to the graveyard after it resolves. [D'Angelo 1998/11/04]
The second ability is a replacement ability (see Rule 614). It applies to both costs and effects. [WotC Rules Team 1998/11/03] There is no infinite loop mana generation with Dark Ritual. [D'Angelo 1998/11/04]
It will remove itself from the game since it goes to the graveyard after its effect starts. [D'Angelo 1998/11/04]
